A central processing unit (CPU) may include or cooperate with one or more levels of a cache hierarchy in order to facilitate quick access to data. This is accomplished by reducing the latency of a CPU request of data in memory for a read or a write operation. Generally, a data cache is divided into sections of equal capacity, called cache “ways”, and the data cache may store one or more blocks within the cache ways. Each block is a copy of data stored at a corresponding address in the system memory.
Cache ways are accessed to locate a specific block of data, and the energy expenditure increases with the number of cache ways that must be accessed. For this reason, it is beneficial to utilize methods of operation that limit the number of ways that are necessarily accessed in the search for a particular block of data.